1. Field of the Invention
The present invention relates to a device for the high speed mixing of a plurality of materials and specifically to a high speed mixing device for uniformly dispersing solids within a viscous liquid slurry to produce a homogeneous product.
2. Description of the Prior Art
A large variety of manufacturing processes call for the uniform dispersion of dissimilar materials to produce a homogeneous slurry product. Often, the starting materials are lumpy, high viscosity fluid mixtures of materials such as paint formulations, inks adhesive compositions, natural and synthetic latices, and the like. In the case of many paint formulations, a pigment is supplied as a very fine powder which must be uniformly dispersed within a viscous resin/solvent carrier to produce a master batch. The master batch is then tinted to produce the desired paint color.
Certain of the prior art devices have utilized sand, grit, shot or ceramic balls within the slurry as it passed through the mixing device to achieve a more uniform mixture. However, these added media have tended to produce accelerated wear on the equipment due to their abrasive nature. Also, in order to use such added media, the liquid carrier was required to be relatively thin, making the technique unsuitable for highly viscous slurries.
Various prior art mixing devices are known with cone-shaped rotor or stator parts. However, the continuous increase of the mass acceleration in the direction of the converging passage can result in uneven mixing intensity.
Other devices are known which feature concentric cylinder rotor and stator parts. In certain of the prior art devices, the rotor inside the cylindrical housing is provided with axially intermittent cylindrical sections having a diameter smaller than the diameter of the housing. In other sections, the rotor outside diameter is substantially equal to the inside diameter of the housing, thereby subjecting the slurry product to multiple interruptions. Multiple edge mixers are also known in the prior art.
None of the prior art devices, to my knowledge, have been successful in producing a uniform dispersion of a highly viscous, lumpy slurry of the type encountered with paints, lacquers, inks and plastics.
The present invention has as its object to provide a mixing apparatus for producing a uniform dispersion from lumpy, highly viscous slurries without the addition of solid media such as sand, grit, shot or ceramic balls.
Another object of the invention is to provide a concentric cylinder rotating mixer having a cylindrical rotor which has an improved useful life span, even when mixing solid particulate materials with viscous and tacky slurries.
Another object of the invention is to provide an apparatus which will uniformly disperse dry paint pigment in a resin/solvent carrier to produce a continuous, homogeneous product.